In centrifuges a bowl that carries a sample to be separated is rotatably driven by a stationary motor, often supported by some type of resilient support system. In continuous blood separation centrifuges, whole blood is supplied to the rotating bowl and separated fractions are removed from the rotating bowl through flow paths having some segments that rotate with the bowl and other segments that are stationary and are connected to the donor/patient or collection bags on a control monitor. In some operations a sealless connection is provided between rotating and stationary segments by tubes that are carried by an arm that rotates at one-half of the bowl speed. In prior art centrifuge systems, rotating components have been statically and dynamically balanced with respect to the rotation axis to reduce vibration.